NewsForge: Pipes and Filters

“I still remember the day, many years ago, when a wise old
programmer looked over my shoulder and said, ‘Ah, Grasshopper, you
need a pipe!’ and so set me on the path to true enlightenment.

“A pipe is a means by which the output from one process becomes
the input to a second. In technical terms, the standard output
(stout) of one command is sent to the standard input (stdin) of a
second command…”

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